Seal for a tobacco container



July 16, 1968 J. w. 01.0. JR

SEAL FOR A TOBACCO CONTAINER Filed Aug. 25, 1965 Tic E.

h O J E T N NL 1 A N M m 3 w 7 .H kw Q82 fl Z 1 w 2 fi////// I] A (5 2 vB w 4 (5 m flu Wm--. 1! y W United States Patent 3,392,873 SEAL FOR ATOBACCO CONTAINER Jonathan W. Old, Jr., Greenwich, Conn., assignor toLiggett & Myers Tobacco Co., New York, N.Y., a corporation of New JerseyFiled Aug. 25, 1965, Ser. No. 482,374 16 Claims. (Cl. 220-60) ABSTRACTOF THE DISCLOSURE The cap is formed with a pair of spaced dependingflanges to engage two spaced sealing surfaces with the formation of anentrapped volume of air between the seals. The cap bulges at its centerto exert a force on the inner flange to press it against the innersealing surface.

This invention relates to the provision of a seal on a tobaccocontainer, and more particularly to a construction which achieves twobarrier seals between the inside and the outside of a tobacco container,each of these seals being confined to a narrow sealing areacircumference and each being maintained under pressure.

The problem of providing a simple yet effective cap for a rigidcontainer is an old one. Vast sums have been spent to perfect the idealcap, and a great many constructions are known to the art, see forexample the following patents, and the references cited therein: Earl S.Tupper 2,487,400; Edward C. Hicks 2,546,599; Donald W. Hill 2,606,586;Kenneth E. Rosenlof 2,630,237; William J. Poole 2,638,261; Nathan W.Roop 2,695,115; Earl S. Tupper 2,802,590; Earl S. Tupper 2,901,098;Earle H. Barclay 2,990,998; Grant S. Gilbert 2,997,788; Earl S. Tupper3,044,611.

There has remained the need, however, for a cap that could be easily andcheaply manufactured, be used on standard containers, be sufficientlyrigid to give a goo-d packaging appearance and hold the shape of copy orartistic design, and still provide a superior gas and moisture vaporbarrier.

The problem has been particularly acute in the tobacco container art.Pipe tobacco must have a certain moisture content. This moisture iseasily lost to the atmosphere through evaporation. The problem iscritical because pipe tobacco, unlike usual foodstuffs, frequently sitsfor long periods of time on the shelf before it is sold and yet theconsumer is very conscious of whether or not it is stale, or dried out.Moreover, even after it is sold, the tobacco is often taken from the canin small amounts, the cap being removed and replaced after each use.Consequently, the cap must be capable of convenient removal andreplacement, and yet it must make a good seal each time. The problem ofproviding an adequate seal has been so severe that some manufacturershave felt compelled to use solid metal containers and caps for pipetobacco, even though this entails a considerable expense.

It is an object of the present invention to provide an inexpensive andeasily manufactured plastic cap which can be used with conventionallymanufactured cans to provide a superior vapor resistant seal that willmeet the standards for tobacco storage.

Further objects and advantages of the invention will be apparent fromthe following more detailed description in which:

FIG. 1 is a side sectional elevation of a tobacco container according otone embodiment of the invention;

FIG. 2 is a side sectional view of a tobacco container ice cap accordingto one embodiment of the invention; and

FIG. 3 is a partial detail view of a container and cap assembly.

According to the present invention, two separate seals are separatelymade against the can which co-operate to provide the vapor barrier.These seals must be widely spaced from one another and the cap should befree from the can in the area between the seals so as to be able to flexin and out slightly and thus maintain pressure on the inner seal asexplained below.

Preferably, volume is enclosed between cap and can in the space betweenthe inner and outer seals. It is thought that the cap and can whenconstructed to enclose such a volume are effective partly becauseto theextent that any gas or vapor circulates in and out past the innersealany vapor that circulates past the inner seal tends to be trapped inthe enclosed volume between the inner and outer seals and thus tends tocirculate back into the can. This recapture of a portion of the vaporthat is displaced past the inner seal, while a small effect, may besignificant when compared to the small total of (net) leakage that canbe tolerated. The recapture volume is shown generally at 21 in FIG. 3.

In particular, a tobacco container or can or canister 1 is manufacturedwith any suitable method and material and to any desired shape, exceptthat the areas in which the two seals are to be formed must be made sothat each of the sealing areas is of a hard smooth material, so thateach of the sealing areas is substantially separated from the other, sothat there is a retaining edge or lip below or forming a part of theouter sealing area, and so that the portion of the container or canisterbetween the two sealing areas is depressed or otherwise constructed (inrelation to the cap to be used) so as not to interfere with the cap inthe sealing action that is hereinafter described. In the particularembodiment shown in FIG. 1, an outer sealing area circumference isprovided at 2, a retaining edge 3 is provided adjacent and as a lowerpart of the sealing area, an inner sealing area circumference isprovided at 4. The inner sealing area 4 must be spaced from the outersealing area 2 by a vapor-tight portion 5 of the can. This portion maybe of any convenient construction or container contour except that itmust be depressed or otherwise made so as not to engage the cap in thearea intermediate the two sealing areas. Preferably, a metal crimp orflange is shaped to provide the outer sealing area circumference 2, theretaining edge 3, and the inner sealing area 4 and the depressed vaporbarrier portion 5. This flange may be crimped to the can side walls, 6,or otherwise attached.

The cap 7 is constructed to provide a downwardly projecting outer flange8 and a downwardly projecting inner flange 9 joined at their upper endsby a portion 10' of the cap construction.

According to the present invention, the cap is made of a semi-rigdmaterial with some elasticity. A high degree of forgiveness allows thecap to shape itself to the can despite some manufacturing variations. Apreferable material is low density polyethylene, for example, apolyethylene having a density of .9 gram per cubic centimeter andavailable for molding with a melt index of 30. The elasticity orresilience of the cap is necessary to provide for the action of theseals as hereinafter described. Other plastics with similarcharacteristics may be used.

The flange 8 is provided with a lower interlocking projection portion 11which is designed to underlay the retaining edge 3 on the can when thecap is in position. The outer seal portion 12 of the flange 8intermediate the top portion and the retaining projection 11 isdimensioned so that when the cap is in its normal relaxed conditionbefore being applied to the can, the diameter of the inner surface 12 isslightly less than the diameter of the outer sealing area 2 on thecontainer. Preferably these two areas are made so that the sealing areawill be relatively narrow and even approach a line contact. Thisachieves a higher pressure per square inch and provides a better seal.

The inner surface 13 of the downwardly projecting inner flange 9 is madeso that with the cap in a normal relaxed position and before beingapplied to the can the surface 13 will have a diameter slightly greaterthan the diameter of the inner sealing area circumference 4 provided onthe can. The flange 9, being of the same material with the rest of thecap will have a small amount of resilience and flexibility. Preferablythe sealing surface 13 is made so that when it is placed downward by thecan surface 4, it is deflected inward. This may be accomplished by aninwardly downwardly slope of the surface 13, especially at 15.

When the cap made as described above is placed on a can as describedabove, the two seals are formed as follows.

The cap is placed on the can by putting it over the can and pushing theouter. circumference down around the edge of the can.

The outer seal is formed as the outer downwardly projecting flange 8,with its retaining lip 11, is stretched and pushed over the outersealing area 2 so that the retaining lip 11 on the cap snaps under theretaining edge 3 on the can. Then, and in position, the intermediateinner surface 12 of the outer flange is in firm contact with the outersealing area circumference 2 on the can to form an outer seal. Also, thecap is restrained about its outer circumference from upward movement offthe can by the interaction of retaining edge 3 and retaining lip 11.

The inner flange 13 on the cap encounters the upper corner portion 14 ofthe inner sealing area circumference 4 of the can. The portion of theinner flange that makes this contact, for example as indicated generallyat 15, is sloped or curved so as to cause a deflection of the flangeinward and allow the face 13 to slide down adjacent to the inner sealingarea 4 on the can. The surface 13, which preferably is made with aslight incline when in relaxed condition, inclines further as its lowerportion is flexed inward. Preferably the upper inner portion 14 on thecan flange is lower than the top 17 of the upper outer portion to helpallow the flange 9 to flex past the sealing surface 14. The surface 13is also inclined further as the portion of the cap 10 and the outerflange 8 of the cap are bent downward with respect to the portion of thecap 10 over the inner flange 9 during installation of the cap. Ineffect, this upward bulging of the central part of the cap tilts theinner flange 9 inward. It should be understood that the amount ofincline and flexing may be very small, since the dimensional variationsbeing compensated for may also be very small.

It can be seen that elasticity in the cap portion 10 intermediate theouter and inner flanges 8 and 9 contributes to the flexing of theflanges, particularly the inner flange, and to the ability of the cap toform a reliable seal on the can despite the slight variation indimension of the sealing surfaces occasioned by normal manufacturingtolerances, especially those encountered in the plastic molding of thecap. Moreover, it should be understood that the semi-rigid plasticmaterial of the cap and the rigid, preferably metal, material of the canhave different coeflicients of expansion. Even if the fit is perfect atnormal room temperature, it will loosen and tighten as it is exposed tothe ranges of temperature experienced in the course of shipment andstorage.

Or the inner sealing area 1 on the can may be slope or curved at 14.

Specifically, as the outer and retaining lip of the cap is shoved on thecan, a portion 10 of the cap is deflected upwardly by the relativelyupward thrust of the flange 9 as resistance to its downward movement isgenerated by its action against the can surface 4. This deflectionproduces a downward spring-like pressure which urges the slightlyinclined, tilted and flexed inner flange 9 against the sealing area 4and this spring pressure provides considerable compensation forvariations in fit by pressing the flange further down if it is arelatively loose fit or, remaining somewhat deflected upwardly if it isa relatively tight fit. This degree of deflection of the top does notinterfere with the appearance or general serviceability of the cap, butit does provide for always forming a seal on the inner flange. It shouldbe understood that the deflections may be greater or less than is shownin FIG. 3. If the manufacturing tolerances, the differences incoeflicient of expansion or the rigidity of the cap material require,the outer surface of the inner flange 9 can be angled slightly inwardlyaway from the point 16 where the surface intersects the top portion ofthe cap 10. This achieves a greater lateral component of surface 13movement toward the inner sealing area 4 on the can as the inner flange9 is moved downwardly than is otherwise achieved by such downwardmovement.

It is possible to manufacture a cap and can construction that provides adouble seal or vapor barrier by various techniques that can be employedin a factory. A double seal barrier for tobacco cans must be one thatcan be repeatedly made in the home for it will be appreciated thattobacco is used from tobacco cans a little bit at a time and that it iscritical for the double seal barrier to be re-established after eachpipe or pouchful of tobacco is removed from the can. The presentconstruction provides a cap that will form the double seal with onlygentle hand pressure being used to press the outer flange down over theretaining lip about the can. This ease of assembling cap and can isalso, of course, advantageous in manufacturing.

In view of the illustrated embodiment of the invention, other forms willbe apparent to those skilled in the art.

I claim:

1. In combination with a can having an outer sealing area circumference,a separate inner sealing area circumference spaced from said outersealing area circumference, and an outer retaining edge; a cap having atop portion; a downwardly extending outer flange, the inner surface ofsaid outer flange dimensioned so that with the cap in a normal relaxedcondition it is slightly smaller than the dimension of the outer sealingarea circumference on the can, said outer flange having at the bottomportion thereof an inwardly extending retaining lip adapted to engagethe outer retaining edge on the can; and a downwardly projecting innerflange, the outer surface of said inner flange being dimensioned so thatwith the cap in a normal relaxed condition it is slightly greater thanthe dimension of the inner sealing area circumference on the can anddisposed on a downward inward slope.

2. A cap and can assembly having an outer seal formed by an outercircumferential sealing area about the can adjacent an open end thereofin co-operation with an overlying circumferential sealing area about theinner surface of a flange projecting downwardly from the top of the capand having an inner seal formed by an inner circumferential sealing areaabout the can adjacent the same said open end thereof, said innercircumference sealing area on the can being spaced from said outercircumference sealing area on the can, in co-operation with acircumferential sealing area on an inner flange projecting downwardlyfrom the top of the cap, and overcomeable axial restraining meansholding the cap from axial displacement off the can.

3. The assembly of claim 2, supra, in which said inner circumferentialsealing area circumference about the can is displaced inwardly from thesaid open end of the can to which it is adjacent.

4. The assembly of claim 2 in which said axial restraining meanscomprise an outer restraining edge on the can and a retaining lip on thecap for engagement therewith.

5. A cap and can assembly having an outer seal formed by an outercircumferential sealing area about the can adjacent an open end thereofin co-operation with an overlying circumferential sealing area about theinner surface of a flange projecting downwardly from the top of the capand having an inner seal formed by an inner circumferential sealing areaabout the can adjacent the same said open end thereof, said innercircumference sealing area on the can being spaced from said outercircumference sealing area on the can, in co-operation with acircumferential sealing area on an inner flange projecting downwardlyfrom the top of the cap, and overcomeable axial restraining meansholding the cap from axial displacement olf the can, the portion of thetop of the cap above the inner flange being deflected upwardly withrespect to the area of the cap over the outer flange, relative to theirrespective positions when said cap is in a normal relaxed condition sothat there is generated a downward spring pressure urging thecircumferential sealing area of the said inner flange against said innercircumference sealing area on the can.

6. A cap and can assembly having an outer seal formed by an outercircumferential sealing area about the can adjacent an open end thereofin co-operation with an overlying circumferential sealing area about theinner surface of a flange projecting downwardly from the top of the capand having an inner seal formed by an inner circumferential sealing areaabout the can adjacent the same said open end thereof, said innercircumference sealing area on the can being spaced from said outercircumference sealing area on the can, in co-operation with acircumferential sealing area about the outer surface on an inner flangeprojecting downwardly from the top of the cap, said sealing area on saidinner flange being inclined parallel to a cone having its apex on theinward side of said cap, and overcomeable axial restraining meansholding the cap from' axial displacement off the can, said meansincluding an outer restraining edge on the can and a retaining lip onthe cap for engagement therewith.

7. -A cap adapted for closing a can having an outer sealing areacircumference adjacent one end, an inner sealing area circumferencespaced from the outer sealing area circumference and a depressed vaporbarrier portion connecting the outer and inner sealing areacircumference; said cap having a circular top portion beingsubstantially flat when in relaxed condition, a downwardly projectingouter flange dimensioned to a stretch fit about the outer sealing areacircumference of the can, means for retaining said outer flange on saidcan against forces applied inwardly of said outer flange, a downwardlyprojecting inner flange having a surface thereon with a portion thereofinclined downwardly inwardly from said top portion into the can, saidinner flange having a base where said surface joins the underside ofsaid top portion dimensioned slightly larger than the dimension of theinner sealing area circumference on the can and a bottom portion of saidsurface dimensioned slightly smaller than the inner sealing areacircumference on the can whereby when said cap is in position on the canthe intermediate portion of said surface of said inner flange engagesthe inner sealing area circumference of the can causing an upwarddeflection of said top portion and a reactive downward spring pressureforce holding the surface of said inner flange against the inner sealingarea circumference of the can.

8. The cap of claim 7 in which the means for retaining the cap andthereby the top from being removed from the can by force applied inwardof said outer flange comprises a retaining lip about the lower end ofthe outer flange on the cap extending inwardly of said outer flange andadapted to engage an edge on the can.

9. The cap of claim 7 in which a leveling flange is provided on the topside of the top of said cap, said leveling flange located adjacent tothe outer edge of the top, so that when the portion of the top above theinner flange is deflected upwardly when the cap is installed upon thecan, the flange top remains above the top of the cap and continues toprovide a flat surface so that the cans may be stacked on on anotherwithout tipping.

:10. The cap of claim 7 in which the cap portion intermediate thedownwardly projecting outer flange and the downwardly projecting innerflange is constructed to enclose a recapture volume lying intermediatethe cap, the can and the two seals when the cap is installed on saidcan.

11. A cap and can assembly having an outer seal formed by an outercircumferential sealing area about the can adjacent an open end thereof,said outer can sealing area having a retaining portion thereof facingaway from the open end of the can, said outer can area being inco-operation with an overlying circumferential sealing area about theinner surface of a downwardly projecting flange from the cap, said capinner surface being shaped to overlie both the outer sealingcircumference and the said retaining edge portion thereof on the canwhereby a greater pressure within the cap and can assembly than withoutit will result in an increase of pressure experienced by said outerseal, an inner seal formed by an inner circumferential sealing area onsaid can in co-operation with an outer circumferential sealing area on adownwardly projecting inner flange from said cap, said inner surface onthe inner flange of said cap having in position on the can a downwardlyinwardly incline such that a greater pressure outside the cap and canassembly than within it will cause an increase in pressure on said innerseal.

12. A one-piece cap for forming a seal including a flat top,

a first annular flange depending from said flat top and having aretaining lip at the lower end thereof facing inwardly of said flangeand a smooth outer wall surface facing outwardly of said flange, and

a second annular flange depending from said flat top inwardly of saidfirst flange and in spaced relation to said first flange.

13. A one-piece cap for forming a seal including a flat top having abottom planar surface,

a first annular flange depending from said bottom planar surface of saidtop, said flange having a retaining lip at the lower end thereof facinginwardly of said flange and a smooth uninterrupted outer cylindricalwall surface, and

a second annular flange depending from said bottom planar surface ofsaid top, said second flange being spaced inwardly of siad first flange.

14. In combination,

a container having a first sealing area, and a second seaaling areaspaced inwardly of said first sealing area; an

a cap having a top disposed over said container, said top being flat innormal relaxed position and having a bottom planar surface, a firstflange depending from said bottom planar surface of said top in sealingcontact with said first sealing area and a second flange depending fromsaid bottom planar surface of said top inwardly of said first flange insealing contact with said second sealing area, said top having a centralpart bulging upwardly from said container out of said normal relaxedposition to maintain a force on said second flange against said secondsealing surface.

15. The combination as set forth in claim 14 wherein said containerfurther has a retaining edge below said first sealing area and said capfurther has a retaining lip on said first flange in manually removableengagement with said retaining edge.

16. :In combination,

a container having a first sealing area, a second sealing area spacedinwardly of said first sealing area, a re taining edge below said firstsealing area, and a de- References Cited pressed area between said firstand second sealing areas; and UNITED STATES PATENTS a cap having a tOpdisposed over said can, a first flange 3,25 17 19 Gran 220 0 dependingfrom said top in sealing contact with said 5 3 232,477 11 9 Henchrt 22first sealing area and having a retaining lip thereon 3 244 354 4 1956Bauer 220 42 in releaseable engagement with said retaining edge to 3 29,5 1 19 Ruckberg N 2 y 0 hold said cap on said container, and a secondflange 3 297,193 1 19 7 Stevens 22 depending from said top inwardly ofsaid second seals 3 said p avi g a central p gi g p- THERON E. CONDON,Primary Examiner. war y rom said container to tilt said second angeinwardly while maintaining a resilient force on said DONALD NORTONEmmi/my second flange against said second sealing surface. G. T. HALL,Assistant Examiner.

